6 Power charges:
0 Power charges:(DPS times 5 as I fire 5 projectiles)

With all the power charges on the first form has 65% critical chance, that means the secondary form has a critical guarantee. Therefore I'm not investing into critical chance anymore, now is time for the critical multiplier.
Mana cost is 102 per cast, so I had to invest quite a few into mana% and mana regen. Especially with the unique on (-50% mana)

Support skill - for helping out to kill cold resistant monsters faster and a huge support for maps where players have Elemental EquilibriumFireball + Totem + LMP

6 Power charges:
0 Power charges:(DPS times 3 as I fire 5 projectiles)

Support auras
Clarity + Discipline + Reduced mana

Support Curse
Elemental Weakness

Spoiler

Elemental weakness is lvl 17, Frostbite lvl 16, so basicly it decreases the resistance with the same value, the only thing that frosbite adds is the chance to freeze which I do not need with my critical chance % on the other hand I also use the fireball totem so elemntal weakness is more flexible for me.
I have tried the critical weakness as well but i was killing faster when I was cursing them with elemental wekness. (My assumption on that was: Let's say a monster has 50% cold resistance. I cast Critical curse on it, I get 65% more dmg reduced by 50% from the resistance so only 32.5% more damage in final. On the other hand I cast the elem weakness, I get 46% extra damage rigt away)

I've started using this build after searching through the forums for a while.

Is it still working well for you? What level are you on now?

I realize the VP armor is important, as the power charges on crit help immensely with this build, but what would you suggest using before obtaining that piece? Hopefully we can get some more discussion on this build.

I have a similar which, now in legacy. The problem i found was that i can´t get my ES up since VP has so low ES. How do you get 6k ES??

I believe he picks up a few +ES nodes. And once you hit end game gear getting 6k ES isn't difficult. I have in default right now, its not even the best shield. Considering I picked up the 3 nodes that give you 90%(total) more ES from your shield and off the top of my head +60% max ES from other nodes, it doesn't take too long to hit 6k.

I believe he picks up a few +ES nodes. And once you hit end game gear getting 6k ES isn't difficult.

Exactly. Check the passive tree, I picked quite a lot of ES passives knowing I would need them as the Unique chest is not exatly a late game type of armour. (Check the shadow build of the week 14 he has 6link chest with 982 ES, its not even funny, makes me feel all my efforts in the game are futile)

@DemonicGoblin
I stopped at 73 as there was no fun anymore, trying to get high level maps so your experience goes faster than 0.2% per 10 minutes of gamepley really gets boring if you are not trying to get to the top 10.

About VP.
I started the witch knowing I want to try this. So every day I would ask for VP on global. Not all the time - I dont want to troll, just rarely, but every day. Noone seemed to have it for several days and then somene posted the unique dropping for him. I Immediatelly contaceted the person, explained how much I want it and that I want to try a build and he gave it to me very VERY cheap. So I got the lvl 35 VP when I was 38, so you can say I had it the whole time.
Anyway any to your lvl apropriate ES armour would be the substitute here, just don't spent your passives on +1 power charges until you have it as there is no point in that (assuming you know power siphon is not an option for this kind of build)